University of Ottawa

Displaying 1-40 of 75 results

  • White Papers // Jan 2015

    Matching Theory for Backhaul Management in Small Cell Networks with mmWave Capabilities

    Designing cost-effective and scalable backhaul solutions is one of the main challenges for emerging wireless Small Cell Networks (SCNs). In this regard, millimeter Wave (mmW) communication technologies have recently emerged as an attractive solution to realize the vision of a high-speed and reliable wireless Small Cell Backhaul Network (SCBN). In...

    Provided By University of Ottawa

  • White Papers // Nov 2014

    A Deep Learning Model for Structured Outputs with High-order Interaction

    Many real-world applications are associated with structured data, where not only input but also output has interplay. However, typical classification and regression models often lack the ability of simultaneously exploring high-order interaction within input and that within output. In this paper, the authors present a deep learning model aiming to...

    Provided By University of Ottawa

  • White Papers // Sep 2014

    Carrier Aggregation/Channel Bonding in Next Generation Cellular Networks: Methods and Challenges

    To provide cellular systems with additional spectral resources, the wireless industry is considering the aggregation of frequency carriers in licensed, unlicensed, and Shared Access (SA) bands. In this paper, the authors focus on reliable Carrier Aggregation/Channel Bonding (CA/CB) techniques, in which when CA/CB between the licensed, unlicensed and SA carriers...

    Provided By University of Ottawa

  • White Papers // May 2014

    Cache-Enabled Small Cell Networks: Modeling and Tradeoffs

    The authors consider the problem of caching in next generation mobile cellular networks where Small Base Stations (SBSs) are able to store their users' content and serve them accordingly. The SBSs are stochastically distributed over the plane and serve their users either from the local cache or internet via limited...

    Provided By University of Ottawa

  • White Papers // Jul 2013

    Secure Hierarchical Virtual Private LAN Services for Provider Provisioned Networks

    Virtual Private LAN Service (VPLS) is a widely used Layer 2 (L2) Virtual Private Network (VPN) service. Initially, VPLS architectures were proposed as flat architectures. They were used only for small and medium scale networks due to the lack of scalability. Hierarchical VPLS architectures are proposed to overcome these scalability...

    Provided By University of Ottawa

  • White Papers // May 2013

    Technology Based-Entrepreneurship: Measurement Technology Perspective

    Currently, there are several papers on the New Technology Based Firms (NTBFs) yet the case studies of measurement technology appear to not be available. This paper aims to present the entrepreneurial processes of Finnish measurement technology firms. Eight interviews were conducted with the key players of the industry. Successfully, the...

    Provided By University of Ottawa

  • White Papers // Mar 2013

    Spatial Throughput of Wireless Networks Under Different Decoding Rules

    In this paper, the authors revisit the problem of characterizing the highest spatial throughput - or spatial capacity - of wireless networks in [bits/s/Hz/m2] in light of some recent results. They analyze the expected maximum achievable sum rates over a given area based on the capacity regions of Gaussian point-to-point...

    Provided By University of Ottawa

  • White Papers // Feb 2013

    Collaboration in Cloud Businesses - Value Networks and Ecosystems

    Cloud computing businesses are coined by broad and intense company collaboration. There is a growing need for clarification of the types of collaborative structures. In this paper, the authors draw on existing scientific discussions from the fields of value networks and business ecosystems and provide a typology of organisational collaboration...

    Provided By University of Ottawa

  • White Papers // Jan 2013

    Backhaul-Aware Self-Organizing Operator-Shared Small-Cell Networks

    Despite its notable importance, backhauling has - thus far - been a largely overlooked issue. However, driven by the uptake of small cell networks, current dedicated backhaul solutions are no longer viable for mobile operators, calling for novel deployment and backhaul-aware access strategies. In this paper, following the market's latest...

    Provided By University of Ottawa

  • White Papers // Nov 2012

    Reducing the Size of Databases for Multirelational Classification: a Subgraph-based Approach

    Multirelational classification aims to discover patterns across multiple interlinked tables (relations) in a relational database. In many large organizations, such a database often spans numerous departments and/or subdivisions, which are involved in different aspects of the enterprise such as customer profiling, fraud detection, inventory management, financial management and so on....

    Provided By University of Ottawa

  • White Papers // Nov 2012

    Decentralized Linear Transceiver Design in Coordinated Multi-Cell Multiuser MIMO Systems

    This paper considers a downlink linear transmit and receive beamformer design in a coordinated multi-cell network where each multiantenna Base Station (BS) serves its own set of multiple antenna users. Optimization objective is to minimize sum transmission power among coordinated BSs while satisfying user specific minimum SINR targets. The problem...

    Provided By University of Ottawa

  • White Papers // Oct 2012

    One Step Closer Towards e-Business - The Implementation of a Supporting ICT System

    This paper first reviews the thinking behind the Information and Communication Technology (ICT) utilization in supply chain integration as well as in e-supply design. This constructive research is conducted in a real life business network consisting of a number of Small and Medium-sized Enterprises (SMEs) operating in cooperation with one...

    Provided By University of Ottawa

  • White Papers // Oct 2012

    Iterative Classification for Multiple Target Attributes

    Many real-world applications require the simultaneous prediction of multiple target attributes. The techniques currently available for these problems either employ a global model that simultaneously predicts all target attributes or rely on the aggregation of individual models, each predicting one target. This paper introduces a novel solution. The authors' approach...

    Provided By University of Ottawa

  • White Papers // Sep 2012

    Rethinking Offload: How to Intelligently Combine Wi-Fi and Small Cells?

    As future Small Cell Base Stations (SCBSs) are set to be multi-mode capable (i.e., transmitting on both licensed and unlicensed bands), a cost-effective integration of both technologies/ systems coping with peak data demands, is crucial. Using tools from Reinforcement Learning (RL), a distributed cross-system traffic steering framework is proposed, whereby...

    Provided By University of Ottawa

  • White Papers // Sep 2012

    Two-Level Decomposition Method for Resource Allocation in Telecommunication Networks

    In this paper, the authors consider a two-level problem of resource allocation in a telecommunication network divided into zones. At the upper level the network manager distributes homogeneous resource shares among zones in order to maximize the total network profit, which takes into account the inner zonal payments from users...

    Provided By University of Ottawa

  • White Papers // May 2012

    Constellation Design and Mapping for Partially Coherent Correlated Channel With Coding

    Space-Time (ST) constellation design problem and bit mapping schemes for Multiple-Input Multiple-Output (MIMO) systems in correlated Rayleigh fading channels with imperfect channel estimation at the receiver are considered. The channel coefficients are assumed to be correlated in space and uncorrelated in time from one coherence interval to another after which...

    Provided By University of Ottawa

  • White Papers // May 2012

    Successive Zero-Forcing DPC With Per-Antenna Power Constraint: Optimal and Suboptimal Designs

    This paper considers the pre-coder designs for Successive Zero-Forcing Dirty Paper Coding (SZF-DPC), a suboptimal transmission technique for MIMO Broadcast Channels (MIMO BCs). Existing pre-coder designs for SZF-DPC often consider a sum power constraint. In this paper, the authors address the pre-coder design for SZF-DPC with Per-Antenna Power Constraints (PAPCs),...

    Provided By University of Ottawa

  • White Papers // May 2012

    Coordinated Downlink Precoder Design for Regenerative Multi-User Relaying

    Regenerative relaying is an efficient method of increasing the achievable capacity and cell coverage. The authors propose a weighted mean squared error (WMSE) minimization based throughput maximizing precoder design subject to separate sum transmit power constraints for the base station (BS) and relay station (RS). The proposed algorithm is implemented...

    Provided By University of Ottawa

  • White Papers // May 2012

    Learning Coarse Correlated Equilibria in Two-Tier Wireless Networks

    In this paper, the authors study the strategic coexistence between macro and femto cell tiers from a game theoretic learning perspective. A novel regret-based learning algorithm is proposed whereby cognitive femtocells mitigate their interference toward the macrocell tier, on the downlink. The proposed algorithm is fully decentralized relying only on...

    Provided By University of Ottawa

  • White Papers // May 2012

    Error Resistant Lossless Data Compression With Equal Length Coding Using Fine Tuned Multiple Label Mapping

    Data inherently including memory can be compressed using either equal or variable length coding. This paper proposes a novel method to compress the data with memory by using equal length code words while maintaining the error correction capability. The main drawback of Variable Length Coding (VLC) is that because of...

    Provided By University of Ottawa

  • White Papers // May 2012

    Successive Zero-Forcing DPC With Sum Power Constraint: Low-Complexity Optimal Designs

    Successive Zero-Forcing Dirty Paper Coding (SZFDPC) is a simplified alternative to DPC for MIMO Broadcast Channels (MIMO BCs). In the SZF-DPC scheme, the non-causally known interference is canceled by DPC, while the residual interference is suppressed by the ZF technique. Due to the ZF constraints, the precoders are constrained to...

    Provided By University of Ottawa

  • White Papers // May 2012

    Expressivity of Time-Varying Graphs and the Power of Waiting in Dynamic Networks

    In infrastructure-less highly dynamic networks, computing and performing even basic tasks (such as routing and broadcasting) is a very challenging activity due to the fact that connectivity does not necessarily hold, and the network may actually be disconnected at every time instant. Clearly the task of designing protocols for these...

    Provided By University of Ottawa

  • White Papers // Apr 2012

    Implementation of LS, MMSE and SAGE Channel Estimators for Mobile MIMO-OFDM

    The use of Decision Directed (DD) channel estimation in a Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) downlink receiver is explained in this paper. The 3GPP Long Term Evolution (LTE) based pilot structure is used as a benchmark. The Space-Alternating Generalized Expectation-maximization (SAGE) algorithm is used to improve the...

    Provided By University of Ottawa

  • White Papers // Apr 2012

    Building Fastest Broadcast Trees in Periodically-Varying Graphs

    Delay-Tolerant Networks (DTNs) are characterized by a possible absence of end-to-end communication routes at any instant. Still, connectivity can generally be established over time and space. The optimality of a temporal path (journey) in this context can be defined in several terms, including topological (e.g. shortest in hops) and temporal...

    Provided By University of Ottawa

  • White Papers // Apr 2012

    Transformation Toward a Cloud Business Model

    Cloud technologies have widely been discussed within telecommunications research and practice. Compared to traditional software product business, the cloud enabled service business can be significantly different in nature. Therefore the transformation resulting in the implementation of cloud technologies can be drastic. There are gaps in current literature in the business...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Performance of Transmit Antenna Selection Physical Layer Security Schemes

    The authors analyze the PHYsical layer (PHY) security of a communication scheme consisting of a multiple antenna transmitter with a single Radio Frequency (RF) chain using Transmitter Antenna Selection (TAS) and a single antenna receiver, in the presence of a sophisticated multiple antenna eavesdropper. They develop closed-form expressions for the...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Cooperative Redundancy Elimination in Data Center Networks With Wireless Cards at Routers

    The authors consider architecture of Data Center Networks (DCN), which adds wireless network card to each router. Existing Redundancy Elimination (RE) mechanisms reduce link loads and increase network capacity in several environments by removing strings that have appeared in earlier packets through encoding and decode them several hops downstream. This...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Energy Efficient MIMO Two-Way Relay System With Physical Layer Network Coding

    The authors investigate error performance and an optimum power allocation scheme for Multiple-Input Multiple-Output (MIMO) channel Physical layer Network Coding (PNC) based two-way relay system. Zero forcing pre-coding technique is used at source nodes to facilitate PNC operations at the relay node. First, system error performance is investigated by introducing...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    New Double Layer Space-Time Block Code for Distributed 4 X 2 MIMO Systems

    Multiple-Input Multiple-Output (MIMO) techniques have become important part of broadband wireless communication system. Several MIMO Space-Time Block Coding (STBC) techniques have been proposed and widely studied during the last 10 - 15 years and different solutions have been adopted in various wireless standards. The optimal STBC design criteria were proposed...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Hypothesis Testing and Decision Theoretic Approach for Fault Detection in Wireless Sensor Networks

    Sensor networks aim at monitoring their surroundings for event detection and object tracking. But due to failure or death of sensors, false signal can be transmitted. In this paper, the authors consider the problem of fault detection in Wireless Sensor Network (WSN), in particular, addressing both the noise-related measurement error...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Adaptively Secure Broadcast Encryption With Short Ciphertexts

    The authors propose an adaptively secure broadcast encryption scheme with short ciphertexts, where the size of broadcast encryption message is fixed regardless of the size of the broadcast group. In their proposed scheme, members can join and leave the group without requiring any change to public parameters of the system...

    Provided By University of Ottawa

  • White Papers // Feb 2012

    Time-Varying Graphs and Dynamic Networks

    The past few years have seen intensive research efforts carried out in some apparently unrelated areas of dynamic systems - delay-tolerant networks, opportunistic-mobility networks, social networks - obtaining closely related insights. Indeed, the concepts discovered in these investigations can be viewed as parts of the same conceptual universe; and the...

    Provided By University of Ottawa

  • White Papers // Feb 2012

    On the Feasibility of Maintenance Algorithms in Dynamic Graphs

    Near ubiquitous mobile computing has led to intense interest in dynamic graph theory. This provides a new and challenging setting for algorithmic and complexity theory. For any graph-based problem, the rapid evolution of a (possibly disconnected) graph over time naturally leads to the important complexity question: is it better to...

    Provided By University of Ottawa

  • White Papers // Jan 2012

    Distributed Computing in Dynamic Networks: Towards a Framework for Automated Analysis of Algorithms

    Besides the complexity in time or in number of messages, a common approach for analyzing distributed algorithms is to look at the assumptions they make on the underlying network. The authors investigate this question from the perspective of network dynamics. In particular, they ask how a given property on the...

    Provided By University of Ottawa

  • White Papers // Jan 2012

    Successful Performance Measurement in SMEs Through Personnel Participation

    Balanced scorecard has proven to be a functional tool for large companies; however, Small- and Medium-sized Enterprises (SME) have experienced it too complicated for their purposes. The aim of this research is to analyze the potential of simplifying balanced scorecard in order to acknowledge the practical realities of SMEs. The...

    Provided By University of Ottawa

  • White Papers // Nov 2011

    Autoregressive Trust Management in Wireless Ad Hoc Networks

    In this paper, the authors propose a novel trust management scheme for improving routing reliability in wireless ad hoc networks. It is grounded on two classic auto-regression models, namely Auto-Regressive (AR) model and Auto-Regressive with eXogenous inputs (ARX) model. According to this scheme, a node periodically measures the packet forwarding...

    Provided By University of Ottawa

  • White Papers // Oct 2011

    LaConf: A Localized Address Autoconfiguration Scheme for Wireless Ad Hoc Networks

    The authors propose a Localized Address auto-Configuration (LaConf) scheme for wireless ad hoc networks. Address allocation information is maintained on the network border nodes, called Addressing Agents (AAs), which are locally identified by a geographic routing protocol GFG (Greedy-FACE-Greedy). When a node joins the network, it acquires an address from...

    Provided By University of Ottawa

  • White Papers // Sep 2011

    Learning Coarse Correlated Equilibrium in Two-Tier Wireless Networks

    In this paper, the authors study the strategic coexistence between macro and femtocell tiers, from a game theoretic perspective. A novel regret based learning algorithm is proposed whereby cognitive femtocells mitigate their interference toward the macrocell, on the downlink. The proposed algorithm is fully decentralized relying only on the Signal-to-Interference-plus...

    Provided By University of Ottawa

  • White Papers // Sep 2011

    Privacy Disclosure and Preservation in Learning with Multi- Relational Databases

    There has recently been a surge of interest in relational database mining that aims to discover useful patterns across multiple interlinked database relations. It is crucial for a learning algorithm to explore the multiple inter-connected relations so that important attributes are not excluded when mining such relational repositories. However, from...

    Provided By University of Ottawa

  • White Papers // Aug 2011

    On the Temporal Analysis of Scientific Network Evolution

    In this paper, the authors approach the definition of new methodologies for the visualization and the exploration of social networks and their dynamics. They present a recently introduced formalism called TVG (for Time-Varying Graphs), which was initially developed to model and analyze highly-dynamic and infrastructure-less communication networks, and TVG derived...

    Provided By University of Ottawa

  • White Papers // Jan 2010

    Specification and Validation of Telephone Systems in LOTOS

    LOTOS (Language of Temporal Ordering Specification) is a Formal Description Technique that was developed by the ISO for the specification of OSI services and protocols. This paper presents a design methodology for the description in LOTOS of telephone systems with modern telephone features. The description of a Sample Telephone System...

    Provided By University of Ottawa

  • White Papers // Jan 2010

    GPS Based Distributed Routing Algorithms for Wireless Networks

    Recently, several fully distributed (localized) GPS based routing protocols for a Mobile Ad hoc NETwork (MANET) were reported in literature. They are variations of directional (DIR) routing methods, in which node A (the source or intermediate node) transmits a message m to several neighbors whose direction is closest to the...

    Provided By University of Ottawa

  • White Papers // Mar 2010

    On The Determinants Of The Reach Of Innovation-Related Collaboration In Small Firms

    This paper takes as its starting point an item of relatively recent academic orthodoxy: the insistence that 'Interactive learning and collective entrepreneurship are fundamental to the process of innovation' (Lundvall, 1992, p. 9). From this, academics have frequently taken "Interactive" to imply "Inter-organisational" and, whilst one might be concerned by...

    Provided By University of Ottawa

  • White Papers // Nov 2012

    Reducing the Size of Databases for Multirelational Classification: a Subgraph-based Approach

    Multirelational classification aims to discover patterns across multiple interlinked tables (relations) in a relational database. In many large organizations, such a database often spans numerous departments and/or subdivisions, which are involved in different aspects of the enterprise such as customer profiling, fraud detection, inventory management, financial management and so on....

    Provided By University of Ottawa

  • White Papers // Sep 2011

    Privacy Disclosure and Preservation in Learning with Multi- Relational Databases

    There has recently been a surge of interest in relational database mining that aims to discover useful patterns across multiple interlinked database relations. It is crucial for a learning algorithm to explore the multiple inter-connected relations so that important attributes are not excluded when mining such relational repositories. However, from...

    Provided By University of Ottawa

  • White Papers // Apr 2006

    Multi-view ANNs for Multi-relational Classification

    Artificial Neural Networks (ANNs) provide a general, effective and practical approach for learning complex target functions. However, ANNs are not suitable for handling relational data, where information about the target concept is distributed over multiple related relations. ANNs algorithms usually only explore one relation, the so-called target relation, thus excluding...

    Provided By University of Ottawa

  • White Papers // May 2008

    Learning from Skewed Class Multi-relational Databases

    Relational databases, with vast amounts of data - from financial transactions, marketing surveys, medical records, to health informatics observations - and complex schemas, are ubiquitous in the society. Multi-relational classification algorithms have been proposed to learn from such relational repositories, where multiple interconnected tables (relations) are involved. These methods search...

    Provided By University of Ottawa

  • White Papers // Oct 2009

    Pruning Relations for Substructure Discovery of Multi-relational Databases

    Multi-relational data mining methods discover patterns across multiple interlinked tables (relations) in a relational database. In many large organizations, such a multi-relational database spans numerous departments and/or subdivisions, which are involved in different aspects of the enterprise such as customer profiling, fraud detection, inventory management, financial management, and so on....

    Provided By University of Ottawa

  • White Papers // Nov 2014

    A Deep Learning Model for Structured Outputs with High-order Interaction

    Many real-world applications are associated with structured data, where not only input but also output has interplay. However, typical classification and regression models often lack the ability of simultaneously exploring high-order interaction within input and that within output. In this paper, the authors present a deep learning model aiming to...

    Provided By University of Ottawa

  • White Papers // Aug 2007

    Mining Imbalanced Classes in Multirelational Classification

    Multirelational classification algorithms search for patterns across multiple interlinked tables (relations) in a relational database. This type of method searches for relevant features both from a target relation (in which each tuple is associated with a class label) and relations related to the target, in order to better classify tuples...

    Provided By University of Ottawa

  • White Papers // Feb 2008

    Multirelational Classification: a Multiple View Approach

    Multirelational classification aims at discovering useful patterns across multiple inter-connected tables (relations) in a relational database. Many traditional learning techniques, however, assume a single table or a flat file as input (the so-called propositional algorithms). Existing multirelational classification approaches either "Upgrade" mature propositional learning methods to deal with relational presentation...

    Provided By University of Ottawa

  • White Papers // Oct 2010

    Identifying and Preventing Data Leakage in Multi-relational Classification

    Relational database mining, where data are mined across multiple relations, is increasingly commonplace. When considering a complex database schema, it becomes difficult to identify all possible relationships between attributes from the different relations. That is, seemingly harmless attributes may be linked to confidential information, leading to data leaks when building...

    Provided By University of Ottawa

  • White Papers // Oct 2012

    Iterative Classification for Multiple Target Attributes

    Many real-world applications require the simultaneous prediction of multiple target attributes. The techniques currently available for these problems either employ a global model that simultaneously predicts all target attributes or rely on the aggregation of individual models, each predicting one target. This paper introduces a novel solution. The authors' approach...

    Provided By University of Ottawa

  • White Papers // Apr 2010

    Reasoning With Higher-Order Abstract Syntax and Contexts: A Comparison

    A variety of logical frameworks support the use of Higher-Order Abstract Syntax (HOAS) in representing formal systems given via axioms and inference rules and reasoning about them. In such frameworks, object-level binding is encoded directly using meta-level binding. Although these systems seem superficially the same, they differ in a variety...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Hypothesis Testing and Decision Theoretic Approach for Fault Detection in Wireless Sensor Networks

    Sensor networks aim at monitoring their surroundings for event detection and object tracking. But due to failure or death of sensors, false signal can be transmitted. In this paper, the authors consider the problem of fault detection in Wireless Sensor Network (WSN), in particular, addressing both the noise-related measurement error...

    Provided By University of Ottawa

  • White Papers // May 2012

    Expressivity of Time-Varying Graphs and the Power of Waiting in Dynamic Networks

    In infrastructure-less highly dynamic networks, computing and performing even basic tasks (such as routing and broadcasting) is a very challenging activity due to the fact that connectivity does not necessarily hold, and the network may actually be disconnected at every time instant. Clearly the task of designing protocols for these...

    Provided By University of Ottawa

  • White Papers // Jan 2012

    Distributed Computing in Dynamic Networks: Towards a Framework for Automated Analysis of Algorithms

    Besides the complexity in time or in number of messages, a common approach for analyzing distributed algorithms is to look at the assumptions they make on the underlying network. The authors investigate this question from the perspective of network dynamics. In particular, they ask how a given property on the...

    Provided By University of Ottawa

  • White Papers // Apr 2012

    Building Fastest Broadcast Trees in Periodically-Varying Graphs

    Delay-Tolerant Networks (DTNs) are characterized by a possible absence of end-to-end communication routes at any instant. Still, connectivity can generally be established over time and space. The optimality of a temporal path (journey) in this context can be defined in several terms, including topological (e.g. shortest in hops) and temporal...

    Provided By University of Ottawa

  • White Papers // Feb 2012

    Time-Varying Graphs and Dynamic Networks

    The past few years have seen intensive research efforts carried out in some apparently unrelated areas of dynamic systems - delay-tolerant networks, opportunistic-mobility networks, social networks - obtaining closely related insights. Indeed, the concepts discovered in these investigations can be viewed as parts of the same conceptual universe; and the...

    Provided By University of Ottawa

  • White Papers // May 2011

    Measuring Temporal Lags in Delay-Tolerant Networks

    Delay-Tolerant Networks (DTNs) are characterized by a possible absence of end-to-end communication routes at any instant. In most cases, however, a form of connectivity can be established over time and space. This particularity leads to consider the relevance of a given route not only in terms of hops (topological length),...

    Provided By University of Ottawa

  • White Papers // Aug 2011

    On the Temporal Analysis of Scientific Network Evolution

    In this paper, the authors approach the definition of new methodologies for the visualization and the exploration of social networks and their dynamics. They present a recently introduced formalism called TVG (for Time-Varying Graphs), which was initially developed to model and analyze highly-dynamic and infrastructure-less communication networks, and TVG derived...

    Provided By University of Ottawa

  • White Papers // Feb 2012

    On the Feasibility of Maintenance Algorithms in Dynamic Graphs

    Near ubiquitous mobile computing has led to intense interest in dynamic graph theory. This provides a new and challenging setting for algorithmic and complexity theory. For any graph-based problem, the rapid evolution of a (possibly disconnected) graph over time naturally leads to the important complexity question: is it better to...

    Provided By University of Ottawa

  • White Papers // May 2010

    Deterministic Computations in Time-Varying Graphs: Broadcasting Under Unstructured Mobility

    Most highly dynamic infrastructure-less networks have in common that the assumption of connectivity does not necessarily hold at a given instant. Still, communication routes can be available between any pair of nodes over time and space. These networks (variously called delay-tolerant, disruptive-tolerant, challenged) are naturally modeled as time-varying graphs (or...

    Provided By University of Ottawa

  • White Papers // Nov 2011

    Autoregressive Trust Management in Wireless Ad Hoc Networks

    In this paper, the authors propose a novel trust management scheme for improving routing reliability in wireless ad hoc networks. It is grounded on two classic auto-regression models, namely Auto-Regressive (AR) model and Auto-Regressive with eXogenous inputs (ARX) model. According to this scheme, a node periodically measures the packet forwarding...

    Provided By University of Ottawa

  • White Papers // Oct 2011

    LaConf: A Localized Address Autoconfiguration Scheme for Wireless Ad Hoc Networks

    The authors propose a Localized Address auto-Configuration (LaConf) scheme for wireless ad hoc networks. Address allocation information is maintained on the network border nodes, called Addressing Agents (AAs), which are locally identified by a geographic routing protocol GFG (Greedy-FACE-Greedy). When a node joins the network, it acquires an address from...

    Provided By University of Ottawa

  • White Papers // Aug 2010

    Localized Address Autoconfiguration in Wireless Ad Hoc Networks

    The authors propose a Localized Address auto-Configuration (LaConf) scheme for wireless ad hoc networks. Address allocation information is maintained on the network border nodes, called Addressing Agents (AAs), which are locally identified by geographic routing protocol GFG. When a node joins the network, it acquires an address from a neighboring...

    Provided By University of Ottawa

  • White Papers // Mar 2010

    Carrier-Based Coverage Augmentation in Wireless Sensor and Robot Networks

    Carrier-based sensor placement involves mobile robots carrying and dropping (static) sensors for optimal coverage formation. Existing solutions target at traditional area coverage problem and unrealistically assume that robots carry sensors all together (ignoring the physical dimension of sensors and the limit of robot capacity). In this paper, the authors consider...

    Provided By University of Ottawa

  • White Papers // Sep 2010

    Priority Channel Selection Based on Detection History Database

    This paper proposes a new database-based two-stage channel selection method for cognitive radios. The proposed method consists of two stages, namely the database collection and signal detection parts. The database collects information about channels. When a cognitive radio needs to find an unoccupied channel for a transmission, it sends a...

    Provided By University of Ottawa

  • White Papers // Sep 2012

    Two-Level Decomposition Method for Resource Allocation in Telecommunication Networks

    In this paper, the authors consider a two-level problem of resource allocation in a telecommunication network divided into zones. At the upper level the network manager distributes homogeneous resource shares among zones in order to maximize the total network profit, which takes into account the inner zonal payments from users...

    Provided By University of Ottawa

  • White Papers // Sep 2012

    Rethinking Offload: How to Intelligently Combine Wi-Fi and Small Cells?

    As future Small Cell Base Stations (SCBSs) are set to be multi-mode capable (i.e., transmitting on both licensed and unlicensed bands), a cost-effective integration of both technologies/ systems coping with peak data demands, is crucial. Using tools from Reinforcement Learning (RL), a distributed cross-system traffic steering framework is proposed, whereby...

    Provided By University of Ottawa

  • White Papers // Nov 2012

    Decentralized Linear Transceiver Design in Coordinated Multi-Cell Multiuser MIMO Systems

    This paper considers a downlink linear transmit and receive beamformer design in a coordinated multi-cell network where each multiantenna Base Station (BS) serves its own set of multiple antenna users. Optimization objective is to minimize sum transmission power among coordinated BSs while satisfying user specific minimum SINR targets. The problem...

    Provided By University of Ottawa

  • White Papers // Jan 2013

    Backhaul-Aware Self-Organizing Operator-Shared Small-Cell Networks

    Despite its notable importance, backhauling has - thus far - been a largely overlooked issue. However, driven by the uptake of small cell networks, current dedicated backhaul solutions are no longer viable for mobile operators, calling for novel deployment and backhaul-aware access strategies. In this paper, following the market's latest...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    Performance of Transmit Antenna Selection Physical Layer Security Schemes

    The authors analyze the PHYsical layer (PHY) security of a communication scheme consisting of a multiple antenna transmitter with a single Radio Frequency (RF) chain using Transmitter Antenna Selection (TAS) and a single antenna receiver, in the presence of a sophisticated multiple antenna eavesdropper. They develop closed-form expressions for the...

    Provided By University of Ottawa

  • White Papers // Mar 2013

    Spatial Throughput of Wireless Networks Under Different Decoding Rules

    In this paper, the authors revisit the problem of characterizing the highest spatial throughput - or spatial capacity - of wireless networks in [bits/s/Hz/m2] in light of some recent results. They analyze the expected maximum achievable sum rates over a given area based on the capacity regions of Gaussian point-to-point...

    Provided By University of Ottawa

  • White Papers // May 2010

    The One-Commodity Traveling Salesman Problem With Selective Pickup and Delivery: An Ant Colony Approach

    The authors introduce a novel combinatorial optimization problem: the One-commodity Traveling Salesman Problem with SELective Pickup and Delivery (1-TSP-SELPD), characterized by the fact that the demand of any delivery customer can be met by a relatively large number of pickup customers. While all delivery spots are to be visited, only...

    Provided By University of Ottawa

  • White Papers // Jan 2011

    Localized Energy Efficient Broadcast for Wireless Networks With Directional Antennas

    Directional antennas reduce the beamwidth angle to diffuse the radio transmission to one direction and thus useless energy than omnidirectional antennas. Combined with the idea of reducing the transmission power, these devices can be used for the minimal energy broadcasting problem. The problem is to minimize the total energy consumption...

    Provided By University of Ottawa

  • White Papers // May 2012

    Error Resistant Lossless Data Compression With Equal Length Coding Using Fine Tuned Multiple Label Mapping

    Data inherently including memory can be compressed using either equal or variable length coding. This paper proposes a novel method to compress the data with memory by using equal length code words while maintaining the error correction capability. The main drawback of Variable Length Coding (VLC) is that because of...

    Provided By University of Ottawa

  • White Papers // May 2012

    Successive Zero-Forcing DPC With Sum Power Constraint: Low-Complexity Optimal Designs

    Successive Zero-Forcing Dirty Paper Coding (SZFDPC) is a simplified alternative to DPC for MIMO Broadcast Channels (MIMO BCs). In the SZF-DPC scheme, the non-causally known interference is canceled by DPC, while the residual interference is suppressed by the ZF technique. Due to the ZF constraints, the precoders are constrained to...

    Provided By University of Ottawa

  • White Papers // Mar 2012

    New Double Layer Space-Time Block Code for Distributed 4 X 2 MIMO Systems

    Multiple-Input Multiple-Output (MIMO) techniques have become important part of broadband wireless communication system. Several MIMO Space-Time Block Coding (STBC) techniques have been proposed and widely studied during the last 10 - 15 years and different solutions have been adopted in various wireless standards. The optimal STBC design criteria were proposed...

    Provided By University of Ottawa

  • White Papers // May 2012

    Coordinated Downlink Precoder Design for Regenerative Multi-User Relaying

    Regenerative relaying is an efficient method of increasing the achievable capacity and cell coverage. The authors propose a weighted mean squared error (WMSE) minimization based throughput maximizing precoder design subject to separate sum transmit power constraints for the base station (BS) and relay station (RS). The proposed algorithm is implemented...

    Provided By University of Ottawa